purchase is not in the wedding list

You can see this article as a guide:

https://docs.nmerimedia.com/nm-gift-registry-and-wishlist/remove-the-link-from-the-product-titles-in-the-wishlist-items-table/

yes ok, this solves but eliminates the ability to view the full description of the product.
It would be a better solution to be able to view the details of the product and purchase it while remaining within the list.

At the moment this can only be done by adding a little extra code to your app as a customization.

how can i get this extra code?

You have to create it yourself or get a developer to do it for you.